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| author | Juan Marín Noguera <juan@mnpi.eu> | 2025-05-16 22:18:44 +0200 |
|---|---|---|
| committer | Juan Marín Noguera <juan@mnpi.eu> | 2025-05-16 22:18:44 +0200 |
| commit | 4f670b750af5c11e1eac16d9cd8556455f89f46a (patch) | |
| tree | e0f8d7b33df2727d89150f799ee8628821fda80a /1.2.2.lyx | |
| parent | 16ccda6c459c0fd7ca2081e9d541124c28b0c556 (diff) | |
Changed layout for more manageable volumes
Diffstat (limited to '1.2.2.lyx')
| -rw-r--r-- | 1.2.2.lyx | 1329 |
1 files changed, 0 insertions, 1329 deletions
diff --git a/1.2.2.lyx b/1.2.2.lyx deleted file mode 100644 index e964905..0000000 --- a/1.2.2.lyx +++ /dev/null @@ -1,1329 +0,0 @@ -#LyX 2.4 created this file. For more info see https://www.lyx.org/ -\lyxformat 620 -\begin_document -\begin_header -\save_transient_properties true -\origin unavailable -\textclass book -\begin_preamble -\input defs -\end_preamble -\use_default_options true -\maintain_unincluded_children no -\language english -\language_package default -\inputencoding utf8 -\fontencoding auto -\font_roman "default" "default" -\font_sans "default" "default" -\font_typewriter "default" "default" -\font_math "auto" "auto" -\font_default_family default -\use_non_tex_fonts false -\font_sc false -\font_roman_osf false -\font_sans_osf false -\font_typewriter_osf false -\font_sf_scale 100 100 -\font_tt_scale 100 100 -\use_microtype false -\use_dash_ligatures true -\graphics default -\default_output_format default -\output_sync 0 -\bibtex_command default -\index_command default -\float_placement class -\float_alignment class -\paperfontsize default -\spacing single -\use_hyperref false -\papersize default -\use_geometry false -\use_package amsmath 1 -\use_package amssymb 1 -\use_package cancel 1 -\use_package esint 1 -\use_package mathdots 1 -\use_package mathtools 1 -\use_package mhchem 1 -\use_package stackrel 1 -\use_package stmaryrd 1 -\use_package undertilde 1 -\cite_engine basic -\cite_engine_type default -\biblio_style plain -\use_bibtopic false -\use_indices false -\paperorientation portrait -\suppress_date false -\justification true -\use_refstyle 1 -\use_formatted_ref 0 -\use_minted 0 -\use_lineno 0 -\index Index -\shortcut idx -\color #008000 -\end_index -\secnumdepth 3 -\tocdepth 3 -\paragraph_separation indent -\paragraph_indentation default -\is_math_indent 0 -\math_numbering_side default -\quotes_style english -\dynamic_quotes 0 -\papercolumns 1 -\papersides 1 -\paperpagestyle default -\tablestyle default -\tracking_changes false -\output_changes false -\change_bars false -\postpone_fragile_content false -\html_math_output 0 -\html_css_as_file 0 -\html_be_strict false -\docbook_table_output 0 -\docbook_mathml_prefix 1 -\end_header - -\begin_body - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -exerc1[00] -\end_layout - -\end_inset - -What is the smallest positive rational number? -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - -There isn't. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -exerc2[00] -\end_layout - -\end_inset - -Is -\begin_inset Formula $1+0.239999999\dots$ -\end_inset - - a decimal expansion? -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - -Yes, - as long as it means a number -\begin_inset Formula $x$ -\end_inset - - with -\begin_inset Formula $1.239999999\leq x<1.24$ -\end_inset - -, - that is, - as long as it doesn't end with an infinite number of nines. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -exerc3[02] -\end_layout - -\end_inset - -What is -\begin_inset Formula $(-3)^{-3}$ -\end_inset - -? -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - - -\begin_inset Formula $(-3)^{-3}=\frac{1}{(-3)^{3}}=\frac{1}{-27}=-\frac{1}{27}$ -\end_inset - -. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -rexerc4[05] -\end_layout - -\end_inset - -What is -\begin_inset Formula $(0.125)^{-2/3}$ -\end_inset - -? -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - - -\begin_inset Formula $(0.125)^{-2/3}=(\frac{1}{8})^{-2/3}=\sqrt[3]{(\frac{1}{8})^{-2}}=\sqrt[3]{8^{2}}=\sqrt[3]{64}=4$ -\end_inset - -. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -exerc5[05] -\end_layout - -\end_inset - -We defined real numbers in terms of a decimal expansion. - Discuss how we could have defined them in terms of a binary expansion instead, - and give a definition to replace Eq. - (2). -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - -A decimal expansion would have the form -\begin_inset Formula $x=n+0.b_{1}b_{2}b_{3}\dots$ -\end_inset - -, - where each -\begin_inset Formula $b_{i}$ -\end_inset - - would be a binary digit, - 0 or 1, - and this would mean that -\begin_inset Formula -\[ -n+\frac{b_{1}}{2}+\frac{b_{2}}{4}+\dots+\frac{b_{k}}{2^{k}}\leq x<n+\frac{b_{1}}{2}+\frac{b_{2}}{4}+\dots+\frac{b_{k}}{2^{k}}+\frac{1}{10^{k}}. -\] - -\end_inset - - -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -exerc6[10] -\end_layout - -\end_inset - -Let -\begin_inset Formula $x=m+0.d_{1}d_{2}\dots$ -\end_inset - - and -\begin_inset Formula $y=n+0.e_{1}e_{2}\dots$ -\end_inset - - be real numbers, - Give a rule for determining whether -\begin_inset Formula $x=y$ -\end_inset - -, - -\begin_inset Formula $x<y$ -\end_inset - -, - or -\begin_inset Formula $x>y$ -\end_inset - -, - based on the decimal representation. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - -We say that -\begin_inset Formula $x=y$ -\end_inset - - if -\begin_inset Formula $m=n$ -\end_inset - - and -\begin_inset Formula $d_{k}=e_{k}$ -\end_inset - - for all -\begin_inset Formula $k$ -\end_inset - -, - and that -\begin_inset Formula $x<y$ -\end_inset - - if -\begin_inset Formula $m<n$ -\end_inset - - or if -\begin_inset Formula $m=n$ -\end_inset - - and there's a -\begin_inset Formula $k$ -\end_inset - - such that -\begin_inset Formula $d_{j}=e_{j}$ -\end_inset - - for -\begin_inset Formula $1\leq j<k$ -\end_inset - - and -\begin_inset Formula $d_{k}<e_{k}$ -\end_inset - -. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -rexerc11[10] -\end_layout - -\end_inset - -If -\begin_inset Formula $b=10$ -\end_inset - - and -\begin_inset Formula $x\approx\log_{10}2$ -\end_inset - -, - to how many decimal places of accuracy will we need to know the value of -\begin_inset Formula $x$ -\end_inset - - in order to determine the first three decimal places of the decimal expansion of -\begin_inset Formula $b^{x}$ -\end_inset - -? -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - -Potentially infinite. - Because -\begin_inset Formula $10^{\log_{10}2}=2$ -\end_inset - -, - -\begin_inset Formula $10^{x}=2.0\dots$ -\end_inset - - if -\begin_inset Formula $x\geq\log_{10}2$ -\end_inset - - or -\begin_inset Formula $10^{x}=1.9\dots$ -\end_inset - - if -\begin_inset Formula $x\leq\log_{10}2$ -\end_inset - -, - but since -\begin_inset Formula $\log_{10}2$ -\end_inset - - is irrational, - its decimal expansion is infinite and, - in the worst case that -\begin_inset Formula $x=\log_{10}2$ -\end_inset - -, - we can't determine by an algorithm that -\begin_inset Formula $x\geq\log_{10}2$ -\end_inset - -. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -exerc12[02] -\end_layout - -\end_inset - -Explain why Eq. - (10) follows from Eqs. - (8). -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - -Because logarithms are strictly increasing, - continuous functions, - and we have that -\begin_inset Formula $10^{0.30102999}<2<10^{0.30103000}$ -\end_inset - -, - we can take logarithms on the expression to get -\begin_inset Formula $0.30102999<\log_{10}2<0.30103000$ -\end_inset - -, - and so -\begin_inset Formula $\log_{10}2=0.30102999$ -\end_inset - -. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -rexerc13[M23] -\end_layout - -\end_inset - - -\end_layout - -\begin_layout Enumerate -Given that -\begin_inset Formula $x$ -\end_inset - - is a positive real number and -\begin_inset Formula $n$ -\end_inset - - is a positive integer, - prove the inequality -\begin_inset Formula $\sqrt[n]{1+x}-1\leq x/n$ -\end_inset - -. -\end_layout - -\begin_layout Enumerate -Use this fact to justify the remarks following (7). -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - - -\end_layout - -\begin_layout Enumerate -Let -\begin_inset Formula $f(x):=\sqrt[n]{1+x}-1-\frac{x}{n}$ -\end_inset - -, - we have to prove that, - if -\begin_inset Formula $n$ -\end_inset - - is a positive integer and -\begin_inset Formula $x>0$ -\end_inset - -, - then -\begin_inset Formula $f(x)\leq0$ -\end_inset - -. - We have -\begin_inset Formula -\[ -f'(x)=\frac{1}{n\sqrt[n]{1+x}}-\frac{1}{n}=\frac{1}{n}\left(\frac{1}{\sqrt[n]{1+x}-1}\right), -\] - -\end_inset - -but since -\begin_inset Formula $\sqrt[n]{1+x}>1$ -\end_inset - - for -\begin_inset Formula $x>0$ -\end_inset - -, - we have -\begin_inset Formula $f'(x)<0$ -\end_inset - - and -\begin_inset Formula $f$ -\end_inset - - is strictly decreasing on -\begin_inset Formula $(0,+\infty)$ -\end_inset - -. - Since -\begin_inset Formula $f(0)=0$ -\end_inset - -, - this proves the result. -\end_layout - -\begin_layout Enumerate -It's clear that -\begin_inset Formula $b^{n+d_{1}/10+\dots+d_{k}/10^{k}}\leq b^{n+1}$ -\end_inset - -, - and then, - taken -\begin_inset Formula $x=b-1>0$ -\end_inset - - and -\begin_inset Formula $n=10^{k}$ -\end_inset - -, - we have -\begin_inset Formula $\sqrt[10^{k}]{1+b-1}=b^{1/10^{k}}\leq(b-1)/10^{k}$ -\end_inset - -. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -exerc15[10] -\end_layout - -\end_inset - -Prove or disprove: -\begin_inset Formula -\begin{align*} -\log_{b}x/y & =\log_{b}x-\log_{b}y, & \text{if }x,y & >0. -\end{align*} - -\end_inset - - -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - -Let -\begin_inset Formula $\alpha:=\log_{b}x$ -\end_inset - - and -\begin_inset Formula $\beta:=\log_{b}y$ -\end_inset - -, - we have -\begin_inset Formula -\[ -\frac{b^{\alpha}}{b^{\beta}}=b^{\alpha}b^{-\beta}=b^{\alpha-\beta}, -\] - -\end_inset - -and taking logarithms, - we get -\begin_inset Formula $\log_{b}\frac{b^{\alpha}}{b^{\beta}}=\log_{b}\frac{x}{y}=\log_{b}b^{\alpha-\beta}=\alpha-\beta=\log_{b}x-\log_{b}y.$ -\end_inset - - -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -exerc16[00] -\end_layout - -\end_inset - -How can -\begin_inset Formula $\log_{10}x$ -\end_inset - - be expressed in terms of -\begin_inset Formula $\ln x$ -\end_inset - - and -\begin_inset Formula $\ln10$ -\end_inset - -? -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - - -\begin_inset Formula $\log_{10}x=\frac{\log_{e}x}{\log_{e}10}=\frac{\ln x}{\ln10}$ -\end_inset - -. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -rexerc17[05] -\end_layout - -\end_inset - -What is -\begin_inset Formula $\lg32$ -\end_inset - -? - -\begin_inset Formula $\log_{\pi}\pi$ -\end_inset - -? - -\begin_inset Formula $\ln e$ -\end_inset - -? - -\begin_inset Formula $\log_{b}1$ -\end_inset - -? - -\begin_inset Formula $\log_{b}(-1)$ -\end_inset - -? -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - - -\begin_inset Formula $\lg32=5$ -\end_inset - -, - -\begin_inset Formula $\log_{\pi}\pi=1$ -\end_inset - -, - -\begin_inset Formula $\ln e=1$ -\end_inset - -, - -\begin_inset Formula $\log_{b}1=0$ -\end_inset - -. - As for -\begin_inset Formula $\log_{b}(-1)$ -\end_inset - -, - it would be an -\begin_inset Formula $x$ -\end_inset - - such that -\begin_inset Formula $b^{x}=-1$ -\end_inset - -, - which is not a real number most of the time. - As a complex number, - it would be -\begin_inset Formula $\log_{b}(-1)=\frac{\ln(-1)}{\ln b}=\frac{i\pi}{\ln b}$ -\end_inset - -, - since -\begin_inset Formula $e^{i\pi}=-1$ -\end_inset - -. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -exerc18[10] -\end_layout - -\end_inset - -Prove or disprove: - -\begin_inset Formula $\log_{8}x=\frac{1}{2}\lg x$ -\end_inset - -. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - - -\begin_inset Formula $\log_{8}x=\frac{\lg x}{\lg8}$ -\end_inset - -, - but -\begin_inset Formula $\lg8=3\neq2$ -\end_inset - -, - so this is false in the general case (this is only true when -\begin_inset Formula $x=1$ -\end_inset - -). -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -rexerc19[20] -\end_layout - -\end_inset - -If -\begin_inset Formula $n$ -\end_inset - - is an integer whose decimal representation is 14 digits long, - will the value of -\begin_inset Formula $n$ -\end_inset - - fit in a computer word with a capacity of 47 bits and a sign bit? -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - -The number of possibilities for a number with up to 14 digits is -\begin_inset Formula $10^{14}$ -\end_inset - -, - and the number for 47 bits is -\begin_inset Formula $2^{47}\approx1.3\cdot2^{14}$ -\end_inset - -, - so it would fit. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -exerc20[10] -\end_layout - -\end_inset - -Is there any simple relation between -\begin_inset Formula $\log_{10}2$ -\end_inset - - and -\begin_inset Formula $\log_{2}10$ -\end_inset - -? -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - - -\begin_inset Formula $\log_{10}2=\frac{\log_{2}2}{\log_{2}10}=\frac{1}{\log_{2}10}$ -\end_inset - -, - so -\begin_inset Formula $\log_{10}2\log_{2}10=1$ -\end_inset - -. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -rexerc22[20] -\end_layout - -\end_inset - -(R. - W. - Hamming.) Prove that -\begin_inset Formula -\[ -\lg x\approx\ln x+\log_{10}x, -\] - -\end_inset - -with less than -\begin_inset Formula $\unit[1]{\%}$ -\end_inset - - error! - (Thus a table of natural logarithms and of common logarithms can be used to get approximate values of binary logarithms as well.) -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - - -\begin_inset Formula -\[ -\ln x+\log_{10}x=\frac{\lg x}{\lg e}+\frac{\lg x}{\lg10}=\lg x\left(\frac{1}{\lg e}+\frac{1}{\lg10}\right)\cong0.994\lg x\approx\lg x, -\] - -\end_inset - -and this gives us about -\begin_inset Formula $\unit[0.6]{\%}$ -\end_inset - - error. -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -rexerc27[M25] -\end_layout - -\end_inset - -Consider the method for calculating -\begin_inset Formula $\log_{10}x$ -\end_inset - - discussed in the text. - Let -\begin_inset Formula $x'_{k}$ -\end_inset - - denote the computed approximation to -\begin_inset Formula $x_{k}$ -\end_inset - -, - determined as follows: - -\begin_inset Formula $x(1-\delta)\leq10^{n}x'_{0}\leq x(1+\epsilon)$ -\end_inset - -; - and in the determination of -\begin_inset Formula $x'_{k}$ -\end_inset - - by Eqs. - (18), - the quantity -\begin_inset Formula $y_{k}$ -\end_inset - - is used in place of -\begin_inset Formula $(x'_{k-1})^{2}$ -\end_inset - -, - where -\begin_inset Formula $(x'_{k-1})^{2}(1-\delta)\leq y_{k}\leq(x'_{k-1})^{2}(1+\epsilon)$ -\end_inset - - and -\begin_inset Formula $1\leq y_{k}<100$ -\end_inset - -. - Here -\begin_inset Formula $\delta$ -\end_inset - - and -\begin_inset Formula $\epsilon$ -\end_inset - - are small constants that reflect the upper and lower errors due to rounding or truncation. - If -\begin_inset Formula $\log^{\prime}x$ -\end_inset - - denotes the result of the calculations, - show that after -\begin_inset Formula $k$ -\end_inset - - steps we have -\begin_inset Formula -\[ -\log_{10}x+2\log_{10}(1-\delta)-1/2^{k}<\log^{\prime}x\leq\log_{10}x+2\log_{10}(1+\epsilon). -\] - -\end_inset - - -\end_layout - -\begin_layout Standard -\begin_inset ERT -status open - -\begin_layout Plain Layout - - -\backslash -answer -\end_layout - -\end_inset - -We first prove by induction that -\begin_inset Formula -\[ -x^{2^{k}}(1-\delta)^{2^{k+1}-1}\leq10^{2^{k}(n+b_{1}/2+\dots+b_{k}/2^{k})}x'_{k}\leq x^{2^{k}}(1+\epsilon)^{2^{k+1}-1}. -\] - -\end_inset - -For -\begin_inset Formula $k=0$ -\end_inset - -, - we have -\begin_inset Formula $x(1-\delta)\leq10^{n}x'_{0}\leq x(1+\epsilon)$ -\end_inset - -, - which is given. - If this holds up to a certain -\begin_inset Formula $k$ -\end_inset - -, - then if -\begin_inset Formula $(x'_{k})^{2}<10$ -\end_inset - -, - we have -\begin_inset Formula $b_{k+1}=0$ -\end_inset - -, - -\begin_inset Formula $(1-\delta)(x'_{k})^{2}\leq x'_{k+1}\leq(1+\epsilon)(x'_{k})^{2}$ -\end_inset - - and -\begin_inset Formula -\begin{eqnarray*} -x^{2^{k+1}}(1-\delta)^{2^{k+2}-1} & = & (x^{2^{k+1}}(1-\delta)^{2^{k+1}-1})^{2}(1-\delta)\\ - & \leq & (10^{2^{k}(n+b_{1}/2+\dots+b_{k}/2^{k})}x'_{k})^{2}(1-\delta)\\ - & \leq & 10^{2^{k+1}(n+b_{1}/2+\dots+b_{k}/2^{k}+b_{k+1}/2^{k+1})}x'_{k+1}\\ - & \leq & (10^{2^{k}(n+b_{1}/2+\dots+b_{k}/2^{k})}x'_{k})^{2}(1+\epsilon)\\ - & \leq & (x^{2^{k}}(1+\epsilon)^{2^{k+1}-1})^{2}(1+\epsilon)=x^{2^{k+1}}(1+\epsilon)^{2^{k+2}-1}. -\end{eqnarray*} - -\end_inset - -If -\begin_inset Formula $(x'_{k})^{2}\geq10$ -\end_inset - -, - we have -\begin_inset Formula $b_{k+1}=1$ -\end_inset - -, - -\begin_inset Formula $(1-\delta)(x'_{k})^{2}\leq10x'_{k+1}\leq(1+\epsilon)(x'_{k})^{2}$ -\end_inset - - and -\begin_inset Formula -\begin{eqnarray*} -x^{2^{k+1}}(1-\delta)^{2^{k+2}-1} & \leq & (10^{2^{k}(n+b_{1}/2+\dots+b_{k}/2^{k})}x'_{k})^{2}(1-\delta)\\ - & \leq & 10^{2^{k+1}(n+b_{1}/2+\dots+b_{k}/2^{k})}10x'_{k+1}\\ - & = & 10^{2^{k+1}(n+b_{1}/2+\dots+b_{k}/2^{k}+b_{k+1}/2^{k+1})}x'_{k+1}\\ - & \leq & (10^{2^{k}(n+b_{1}/2+\dots+b_{k}/2^{k})}x'_{k})^{2}(1+\epsilon)\\ - & \leq & x^{2^{k+1}}(1+\epsilon)^{2^{k+2}-1}. -\end{eqnarray*} - -\end_inset - -Then, - by taking logarithms on the expression, - we get -\begin_inset Formula -\[ -2^{k}\log x+(2^{k+1}-1)\log(1-\delta)\leq2^{k}\log^{\prime}x+\log x'_{k}\leq2^{k}\log x+(2^{k+1}-1)\log(1+\epsilon). -\] - -\end_inset - -Finally, - subtracting -\begin_inset Formula $\log x'_{k}$ -\end_inset - - from all sides, - using that -\begin_inset Formula $-1<-\log(1-\delta)-\log x'_{k}=-\log(x'_{k}(1-\delta))$ -\end_inset - -, - because -\begin_inset Formula $x'_{k}(1-\delta)<10$ -\end_inset - -, - using that -\begin_inset Formula $-\log(1+\epsilon)-\log x'_{k}=-\log(x'_{k}(1+\epsilon))\leq0$ -\end_inset - -, - because -\begin_inset Formula $x'_{k}(1+\epsilon)\geq1$ -\end_inset - -, - and dividing everything by -\begin_inset Formula $2^{k}$ -\end_inset - -, - we get -\begin_inset Formula -\[ -\log x+2\log(1-\delta)-\frac{1}{2^{k}}<\log^{\prime}x\leq\log x+2\log(1+\epsilon), -\] - -\end_inset - -which is precisely what we wanted to prove. -\end_layout - -\end_body -\end_document |
